Sen. Rob Portman says he still needs more information before he decides how he'll vote on a House resolution regarding President Donald Trump's declaration of a national emergency at the southern border.

Earlier this month, Portman, a Republican, said in a statement he would "prefer we work together to find a legislative solution instead of declaring a national emergency that will likely be tied up in the courts."

During a conference call with journalists, Portman said he attended a meeting with Vice President Mike Pence and an assistant attorney general to discuss Trump's national emergency. The Department of Justice defended Trump's approach, Portman said.

Before deciding on how he'll vote on the resolution, Portman said he'd like more information about exactly how Trump will fund the emergency and the effect of diverting funds earmarked for other causes.

The White House expects to pull the funds from a few places, including military construction cash, asset forfeiture funds at Department of Treasury and drug interdiction money at the Department of Defense.